Pump



N O s P A M L D PUMP Filed Nov. 19, 1940 //VV/V70P: DONALD L. MAPSON A TTOPNE Y at... e19, 1943 Q 2,332,157

. UNITED .STATES PATENT. OFFICE PUMP Donald L. Mapson,.Biverside, Calif assignor to Food Corporation, San Jose, cum. a corporation of Delaware Application November 19, 1940, Serial No. 366,206

6 Claims. (Cl. 103-149) taneously feeding a plurality of fluids.

This invention resulted from adiflicult protiem encountered in perfecting a machine for gen- .erating gas. The problem inthi instance was to feed a plurality of fluids from separate sources of supply to a common point where the fluids were mixed to produce the required gas. As the gas in question is the result of a chemical action requiring definite relative proportions of the fluids involved, it was necessary that the fluids be fed in the correct proportion as an exces of any one fluid over the amount required for the chemicalaction results in waste.

In addition to maintaining a constant proportion between the fluids-being fed, this problem also involved varying the rate at which the fluids were fed in order to vary the rate at which the gas was produced, without disturbing the relative proportions of the fluids.

The general type of pump to which this invention relates in principle is such as disclosed in U. S. Letters Patent No. 2,123,781, issued July 12, 1938, to C. J. Huber. This principle involves the idea of progressively collapsing and releas- F18. 3 is a vertical sectional view taken on the line 3-4 of Fig. 2.

Fig.4isaviewsimilartof18. 1 withthecover plate removed and showing the manner in which the pump is assembled.

Fig. 5 is a fragmentary plan view of the pump.

" Referring specifically to the drawing, a preferred formof'pump I ll of the invention comprises a housing Ii having a pair of feet l2. A boss 13 projecting from the housing II is bored at H to receive a bearing l5 and a conventional form of grease seal it, this hearing and seal being pressed into the bore ll. As seen in Fig. 2, the

housing II is provided with a primary bore and a smaller, secondary bore 2|, ther being an annular shoulder 22 formed where these bores meet.

Secured on the housing by screw 2| is a cover plate 25 having a bore 26 (see Fig. 2) which is ing a resilient tube to produce a pumping action.

In adapting this principle to the abov men tioned problem, it is an object of my invention to provide a unitary pump which is adapted to simultaneously pump proportionate amounts of a plurality of separate fluids.

Another object of the present invention is to provide a pump embodying the resilient tube principle in which wear of the tube is reduced to a minimum.

A further object thereof is to provide a pump which may be easily assembled and disassembled. Another object of the present invention is to provide a pump embodying the resilient tube principle in which novel and eiflcient means is employed for mounting the tube in the pump housing.

Still another object thereof is the provision of a pump of the type referred to in which the housing is effectively sealed to prevent leakage of the lubricant provided within the housing.

Other objects and advantages will be made manifest in the following, description, taken in connection with the accompanying drawing, in.

which: I

Fig. 1 is an end elevational view of a preferred embodiment of the pump of this invention.

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fi l.

journalled in the bore 26 of the cover plate 25,

the extension 32 being concentric-with the drive end 3|. Between the portions 3| and 32 of the shaft 30 is an eccentric crank' 83 and an enlarged portion 34 which is concentric with the crank 33.

Slidable on he crank 33 is-a ball-bearing 36 upon which a rotor 31 is slidably mounted. Formed in the periphery of the rotor 31 is a groove 38, thelatter receiving a ring 40 which is also disposed against the shoulder 22 of the housing I I. The ring 40 forms an annular wall' which ser es to divide the housing il into primary and secondary compartments ll and 42 respectively.

, The inside diameter of the ring 40 is slightly greater than the outside diameter of the rotor 31 to permit installing the rotor in the housing ll after the ring 40 is in position as will be described hereinafter.

Mounted in the primary compartment II, as shown in Figs. 2, 3, and 4, is a primary tube 45. End portions 46 of the tube extend through holes it formed in the top wall of the housing i I. The holes 48 are countersunk as indicated 'at 49 in Fig. 3.- Mounted in the secondary compartment 42 is a smaller secondary tube 52, end portions 53 of the latter extending through holes 54 which are smaller but otherwise identical to the.

holes 48. The tubes 45 and. 52 are made of resilithe like.

13 is tightened, the plate 53 forces the nipples '65 and 55 downwardly toward the housing II. The end'portions 46 and 53 of the tubes 45 and 52 respectively are firmly clamped between the countersunk portions ofthe holes 48 and 54 and the beveled ends ii of the nipples 50 and 55. This clamping of the tube ends accomplishes three resuits: First, it seals the connection between the tubes and nipples 50 and 55; second, the tubes are secured against creeping during operation of the pump Ill; and third, the holes 43 and 54 are eflectively sealed to prevent leakage of lubricant with which the housing I l is filled.

In Fig. 3, a indicates the axis of they shaft 30 and 12 indicates the axis of the crank 33. The distance a-b is the throw qfthe crank 33 and twice the distance a-b is the total stroke of the crank 33. I have found that the outside diameter of the rotor 31 is preferably equal to or slightly less than the normal inside diameter of the primary tube 45, as is seen in Fig. 4. The choice of such a diameter for the rotor 31 results in the following three advantages:

.1. Smaller sections of 'the tubes 45 and 52 are collapsed at any given instant, thus increasing the capacity of the pump per revolution. 2. The rotor 31 may be inserted into the housing ll, prior to insertion of the bearing 35, without collapsing the tube 45. This step is shown in Fig. 4 and its advantages are made apparent hereinafter.

3. As only about one-half of the periphery of the rotor 31 contacts the tubes 45 and 52 at any given instant. the wear on the tubes resultin from contact with therotor is greatly reduced.

' The importance of the third advantage is apparent when the movement of the rotor 31 is analyzed. In Fig. 3 the arrow X indicates the direction of rotation of the shaft 30. The arrow Y indicates the direction of the rotation of the 'rotor 31 as it rolls on and progressively collapses the tubes 45 and52. Theoretically, there is no relative movement between the periphery of the rotor 31 and the tubes at the point Z of greatest collapse of the tubes by'the rotor. Relative movement between the rotor 31 and tubes does exist, however, at the opposite side of the rotor indicated at S in Fig. 3. The clearance between the periphery of the rotor and the tubing at S relieves the tubing of considerable wear. It is therefore desirable to reduce the amount of contact between the rotor and tubes, this being accomplished in the pump ID by reducingthe .dimeter of the rotor and proportionately increasing the throw of the crank. The rotor must not be too small. however, because a rotor too'small in diameter has a tendency .to buckle the innermost walls of the tubes. r

The bore. of the housing II is greater in diameter than the bore 2| because the thickness fthe. primary tube 45, when collapsed, is greater than that of the secondary tube 52. It is important that the difference between the collapsed this of the primary and secondary tubes be compensated for in the bore of the housing.

One result of this is that two diameters in the housing provide the shoulder 22 which facilitates assembly of the pump by aligning the ring 40 with the groove of th rotor 31.- Another result is to permit a single rotor to operate on two tubes of different diameters without causing excessive friction between the rotor and one of the tubes.

In assembling the pump II), the tube 52 is first placed in the bore 2| with the tube ends extending through the holes 54. The ring 40 is then placed in the bore 20 against the shoulder 22. The primary tube 45 is now mounted in the bore 20 and the nipples 60 and 65, plate 68, and screw 10 assembled as-shown.

With the shaft in place as seen in Figs. 2 and 4, the rotor 31 is now positioned within the housing before the bearing 35 is installed.- This permits installing the rotor 31 concentrically within the housing II, as shown in Fig. 4, without collapsing the tubes.

The next step is to force the rotor 31 radially into concentric relation with the crank 33 of the shaft 30 as shown in Figs. 2 and 3 and slide the bearing 38 into place.

After the cover plate 25 is mounted on the housing II to complete the assembly of the -which is non-injurious to rubber.

When the'shaft 30 is driven by a suitable source of power in the direction of the arrow X of Fig. 3, the fluid being pumped is drawn into and forced through the tubes 45 and 52 in the directions indicated by the arrows above the nipples 50 in Fig. 3. The pump "I may be driven inv either direction and at any desirable speed.

'During operation of the pump ill, the ring serves to separate the tubes and 52 to retain these in proper alignment with the respective bores of the housing Ii.

I claim as my invention:

1. In a pump, the combination of a housing having a bore and a counterbore; a shaft ro-' tatable in said housing, said shaft having an eccentric portion; a rotor rotatably mounted on the eccentric portion of said shaft; and primary and secondary resilient tubes forming a pair of of said bore and said counterbore, said secondary tube being located in said bore and said primary tube in said counterbore, said tubes being progres'sively collapsed between said rotor and said housing in response to rotation of said shaft.

2. In a pump, the combination of a housing having a bore and a counterbore; a shaft rotatable in said housing, said shaft having an eccentric portion; a rotor rotatably mounted on the eccentric portion of said shaft; primary and secondary resilient tubes forming a pair of juxtaposed loops in said housing, said loops encircling said *rotor, said primary tube having a thickness when collapsed which exceeds the collapsed thickness of said secondary tube by an amount equal to the difference between the radii of said bore and said counterbore, said secondary tube being located in said bore and said primary tube in said counterbore, there being an annular shoulder formed in said housing'at the junction between the bore and the counterbore of'said housing: and an annular ring disposed in counterbore of said housing adjacentsaid shoulder, said ring forming a, separating wall between the loops 01 said primary and secondary tubes, said tubes being progressively collapsed between said rotor and said housing in response to rotation 01 said shalt. a

3. A combination as in claim 2'in which said rotor isi'ormed to provide an annular groove i'or slidrbly receiving said ring and maintaining said ring adjacent said shoulder.

4. In a pump, the combination 01': a housing having a circular bore; a shaitrotatably mounted in concentric relation with said bore, said shaft having an eccentric portion within said housing; a rotor rotatably mounted on said eccentric portion a resilient tube extending about said rotor between said rotor and the bore of said housing, opposite ends of said tube extending externally of said housing through adjacent holes .provided in a walloi said housing; a pair of nipples inserted into the ends of said tube extending externally or said housing, the diam-' eters of the portions of said nipples disposed within said tube ends being greater than the diameter of the holes in said housing through. which said tube extends, the outermost portion each or said nipples being reduced in diameter to provide a shoulder adjacent the end received by'said tube end; a single clamp plate having ,lor receiving the outermost portions of nipples; and means for urging said clamp tetowardsaidhousing.saidplateengaging shoulders of said nipples to urge said nipples toclalnpingrelationwiththeportionsol said vinga bo1e;aresiiient.

the

lllhtantiallycircular loriningaloopinaaidhm:arotatable so shaft in said housing, said shaft having an cecentric crank portion; a rotor in said housing, the outside diameter 01 said rotor being less than the bore of said housing by an amount substanresilient tube, said rotor having a bore which is substantially twice the radial distance from the axis of said shaft to the outermost point of said crank portion; and a bearing having a bore in which said crank portion is slidable, said hearing itself being siidable in the bore of said rotor.

6. In a pump for handling two fluids at diiferent rates of flow, the combination of: a housing having a chamber surrounded by substan- 5 tially cylindrical surfaces; a rotor, the exterior face of which is formed by substantially cylindrical surfaces; means ifor mounting said rotor in said chamber with the axis of said rotor disposed eccentrically in said mamber, and for revolving said rotor in said chamber while thus disposed while permitting said rotor to rotate about its own axis, the space within said chamber being divided by a plane perpendicular to the axis thereof into primary and secondarysections; primary and secondary resilient'tubes forming a pair of loops and disposed respectively in said primary and secondary sections, said primary tube having a larger passage therein and a greater thickness when collapsed than the passage and collapsed thickness respectively of said secondary tube, the minimum radial space provided between said rotor and said housing in said primary section being equal to the collapsed thickness oi said primary tube, while'in said secondary section said minimum radial space is equal to the collapsed thickness or said secondary tube: and means for feeding said fluids to said tubes.

DONALD L. HAPBON.

tially twice the normal outside diameter of said- 

